1. Field of the Invention
The present invention relates to a power source apparatus that generates a power-supply voltage and a power-supply current.
2. Description of Related Art
Conventionally, as a test for an electronic device such as a semiconductor circuit, there is a direct current test in which a predetermined power-supply voltage is applied to the electronic device and a power-supply current is measured at that time.
When such a test is performed, a testing device can include a master circuit and a slave circuit that are provided in parallel as a circuitry for generating a power-supply voltage and a power-supply current in some cases. The master circuit and the slave circuit have the same configuration, thereby generating a power-supply voltage, respectively. These circuits also generate an electric current respectively and output a power-supply current by adding electric currents generated by both circuits.
The master circuit and the slave circuit respectively include an output section that outputs an electric current depending on a given voltage and a control section that adjusts the voltage to be given to the output section. The control section outputs the voltage based on a given reference voltage and a voltage fed back from the voltage output from the output section, thereby adjusting outputs of the master circuit and the slave circuit to obtain a predetermined output.
In addition, the master circuit and the slave circuit output the same current as each other. In other words, when the testing device has one slave circuit, the master circuit and the slave circuit are controlled to output one-half of the power-supply current, respectively. By such a configuration, an electronic device being driven by large current is tested.
However, the master circuit and the slave circuit are controlled independently each other. Thus, when characteristics of elements composing the master circuit and the slave circuit are irregular, an output of each circuit becomes irregular. Therefore, it is not possible to adjust a power-supply voltage and a power-supply current that are supplied to an electronic device with high precision.